81⟩ Mm_struct maintains? a) memory files b) open files c) pipe d) active memory regions
d) active memory regions
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99 Linux Operating System Management Questions And Answers
82⟩ Which system call can be used by a user process to lock a memory so that it cannot be swapped out?
memlock()
83⟩ Is page table per process entity? a) Yes b) No
a) Yes
84⟩ On x86-32 Linux, at which address the user stack resides normally? a) 0×00000000 b) 0x3fff0000 c) 0x7fff0000 d) 0xbfff0000
d) 0xbfff0000
85⟩ Describe the use of strace command
Strace can be used to check the system calls called by the program. So, this can be used for debugging and benchmarking purposes.
86⟩ Which one can be a real time schedule policy? a) SCHED_FIFO b) SCHED_SPF c) SCHED_OTHER d) SCHED_FILO
a) SCHED_FIFO
87⟩ Each process has unique a) fd table b) file table c) inode table d) data block table
a) fd table
88⟩ File descriptor table indexes which kernel structure? a) struct file b) strruct fs_struct c) files_struct d) struct inode
a) struct file
89⟩ Executing the 'cd ..' command when at the root level causes a) Error message indicating the user can't access beyond the root level b) Behavior is unix-flavor dependent c) Results in changing to the 'home' directory d) Nothing happens
d) Nothing happens
90⟩ Switch table is used by a) device special file b) directory file c) fifo d) link file.
a) device special file
91⟩ Printf() uses which system call a) open b) read c) write d) close
c) write
92⟩ Which system call is used to create a hard link? a) hard-link b) link c) symlink d) ln
b) link
93⟩ dup2(1,0) a) closes the stdout and copies the stdin descriptor to stdout b) closes the stdin and copies the stdout descriptor to stdin c) will produce compilation error d) None of the above
b) closes the stdin and copies the stdout descriptor to stdin
94⟩ If the fork() system call returns -1, then it means? a) No new child process is created b) The child process is an orphan c) The child process is in Zombie
a) No new child process is created
95⟩ Which function can be used instead of the dup2 to duplicate the file descriptor? a) read() b) open() c) stat() d) fcntl()
d) fcntl()
96⟩ Below is the code int main() { int fd1, fd2; struct stat buff1, buff2; fd1 = open("1.txt", O_RDWR); fd2 = open("2.txt", O_RDWR | O_APPEND); lseek(fd1, 10000, SEEK_SET); write(fd1, "abcdefghij", 10); write(fd2, "abcdefghij", 10); fstat(fd1, &buff1); fstat(fd2, &buff2); printf(" %d %d", buff1.st_size, buff2.st_size); return 0; } Before running the program, the file 1.txt and 2.txt size is 20 each. What is the output? a) 30 30 b) 100020 20 c) 100030 30 d) 100010 30
d) 100010 30
97⟩ Code snippets str1="45678n" str2="123n" f1 = fopen(file1,RDWR,RWX) f2 = fopen(file1,RDWR,RWX) write(f1,str1,len_str1) write(f2,str2,len_str2) o/p a) 12378 b) 123(newline)8(newline) c) 123(newline)78(newline) d) 45678(newline)123(newline)
b) 123(newline)8(newline)
98⟩ What UNIX command is used to update the modification time of a file? a) time b) modify c) cat d) touch
d) touch
99⟩ When mv f1 f2 is executed which file's inode is freed? a) f1 b) f2 c) new inode will be used d) implementation dependent
b) f2
